Can someone explain how to solve this

The answer is D. Here’s the explanation:
Take out the constants: 20/4 x a^(-4)b(-3)c^(2) / a^(2)b^(-6)c^(5)
Simplify the 20/4 to 5.
Use the Quotient Rule which is x^a / x^b = x^(a-b)
5a^(-4-2)b(-3+6)c(2-5)
Simplify (-4-2) to -6.
Simplify (-3+6) to 3.
Simplify (2-5) to -3.
You’re left with 5a^(-6)b^(3)c^(-3)
Use negative power rule which is x^(-a) = 1/x^(a)
5 x 1/a^(6)b^(3) x 1/c^(3)
Final 5b^(3)/a^(6)c^(3)